Slope

Biography

In mathematics, the slope or gradient of a line is a number that describes the direction of the line on a plane. It is commonly denoted by the letter m, and is defined as the ratio of the vertical change (rise) to the horizontal change (run) between any two distinct points on the line. It is not a direct distance or a direct angle, but a measure of their ratio. The line may be physical, as set by a road surveyor, pictorial as in a diagram of a road or roof, or abstract in pure mathematics. An application of the mathematical concept is found in the grade or gradient in geography and civil engineering. The steepness, incline, or grade of a line is the absolute value of its slope: greater absolute value indicates a steeper line. The line trend is defined as follows: An "increasing" or "ascending" line goes up from left to right and has positive slope: m > 0 {\displaystyle m>0} . A "decreasing" or "descending" line goes down from left to right and has negative slope: m < 0 {\displaystyle m<0} . Special directions are: A "(square) diagonal" line has unit slope: m = 1 {\displaystyle m=1} A "horizontal" line (the graph of a constant function) has zero slope: m = 0 {\displaystyle m=0} . A "vertical" line has undefined or infinite slope (see below). If two points of a road have altitudes y1 and y2, the rise is the difference (y2 − y1) = Δy. Neglecting the Earth's curvature, if the two points have horizontal distance x1 and x2 from a fixed point, the run is (x2 − x1) = Δx. The slope between the two points is the difference ratio: m = Δ y Δ x =

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